The present invention relates to a motion guide device provided with a movable member having a body into which passage constituting members formed of resin material are assembled.
A motion guide device is provided with a track rail on which a rolling member rolling portion is formed and a movable block disposed to be movable along the track rail through a number of rolling members such as bolls or rollers. The movable block is formed with a loaded rolling member rolling portion corresponding to a rolling member rolling portion of the track rail, a rolling member escape passage formed in parallel to the loaded rolling member rolling portion with a predetermined space therefrom, and a pair of rolling member rolling direction changing passages each of which connects the loaded rolling member rolling portion and the rolling member escape passage to each other to thereby constitutes a rolling member circulation passage along which the rolling members circulate.
The applicant of the subject application has proposed a technology, such as Japanese Patent Laid-open Publication No. HEI 7-317762, in which support members (retainers) extending along both side edges of the rolling member rolling groove in a loaded area of the movable block, an escape passage constituting member constituting the escape passage of the rolling member, and inner periphery guide section constituting member constituting an inner periphery guide section of the rolling direction changing passage are integrally formed with a body of the movable block through a resin molding process.
However, in such movable block with which the resin portions or members are integrally formed, when the movable block body has a large size or scale, it is necessary to prepare a large-sized mold, which makes it difficult to manufacture such mold. Furthermore, the support members extending along both the side edges of the rolling member rolling groove have thin thickness and long length. Therefore, there may cause a case that resin may not sufficiently be supplied at the time of the molding, thus being also inconvenient.
In order to solve such problems or inconveniences mentioned above, the applicant of the subject application has also provided a motion guide device in which the support members, the escape passage constituting member and the inner periphery guide section constituting member, which are all formed of resin, were formed as separate units independent from the movable block body and then assembled with the movable block body to thereby make easy the molding process and constitute the movable block.
In such motion guide device, connecting portions of the support members, the escape passage constituting members and the inner periphery guide section constituting members are formed to be continuous so as to make smooth the circulation of the rolling members. That is, at least one of connecting portions of these members is integrally formed.
However, even in such structure, these support members, the escape passage constituting members and the inner periphery guide section constituting members have shapes different from each other and amounts (volumes) of resin shrinkage cavities thereof are also different from each other. Accordingly, in the case where the connecting portions of the support members, the escape passage constituting members and the inner periphery guide section constituting members are integrally formed, the thin and long support members and escape passage constituting members may be flexed and the inner periphery guide section constituting members may be opened, which constitutes a further problem. That is, since the rolling members circulate at high speed in the circulation passage constituted by such support members, escape passage constituting members and inner periphery guide section constituting members, such flexible structure of the support members and the escape passage constituting members and the opening (widening) of the inner periphery guide section constituting members will disturb the smooth circulation of the rolling members in the circulation passage.
The present invention has been conceived in consideration of the above matters, and an object of the present invention is to provide a motion guide device which can be easily manufactured even having a large scale and, moreover, in which the long and thin support members and escape passage constituting members are not flexed and the inner periphery guide section constituting members are not opened (widened).
Hereunder, the present invention will be described. Further, it is to be noted that although reference numerals used in the accompanying drawings are added to respective members or portions by applying ( ) for the sake of easy understanding of the present invention, the present invention is not limited to the embodiments shown in the drawings.
The above object can be achieved according to the present invention by providing a motion guide device which comprises a track member (1) provided with rolling member rolling portions (1b, 1b) and a movable member (2) disposed to be movable along the track member (1) through a number of rolling members (3 - - - ) and in which the movable member (2) is provided with loaded rolling member rolling portions (4d, 4d) corresponding to the rolling member rolling portions (1b, 1b) of the track member (1), rolling member escape passages disposed in parallel to the loaded rolling member rolling portions (4d, 4d) with a predetermined distance and a pair of direction changing passages connecting the loaded rolling member rolling portions (4d, 4d) and the rolling member escape passages to thereby circulate the rolling members,
wherein support members (11, 12, 13) extending along both side edges of the loaded rolling member rolling portions (4d, 4d), escape passage constituting members (14, 14) constituting the rolling member escape passages and a pair of inner periphery guide section constituting members (15a, 15a) constituting the inner peripheral portions of the direction changing passages are formed to be independent from a body (4) of the movable member and also independent from each other and are assembled to the body (4) of the movable member.
According to this invention, since the support members, the escape passage constituting members and the inner periphery guide section constituting members are formed independently from the body of the movable member and from each other, these members can be manufactured by preliminarily calculating amounts of respective shrinkage cavities of the support members, the escape passage constituting members and the inner periphery guide section constituting members. As a result, the long and thin support members and escape passage constituting members can be prevented from being flexed, and the inner periphery guide section constituting members can be also prevented from being opened.
In one preferred embodiment of this invention, the support members act to prevent the rolling members (3 - - - ) from coming off from the loaded rolling member rolling portions (4d, 4d) at a time when the movable member (2) is removed from the track member (1).
In another preferred embodiment of this invention, either one of the inner periphery guide section constituting members (15a, 15a) and the body (4) of the movable member is formed with a positioning recess (24) for positioning the inner periphery guide section constituting members (15a, 15a) with respect to the body (4) of the movable member and the other one thereof is formed with a movable member body positioning protrusion (23) to be engaged with the movable member body positioning recess (24); either one of the inner periphery guide section constituting members (15a, 15a) and the escape passage constituting members (14, 14) is formed with a positioning recess (42) for positioning the escape passage constituting members with respect to the inner periphery guide section constituting members (15a, 15a) and the other one thereof is formed with an escape passage constituting member positioning protrusion (20) to be engaged with the escape passage constituting member positioning recess (42); and either one of the inner periphery guide section constituting members (15a, 15a) and the support members (11, 12, 13) are formed with positioning recesses (11b, 13b, 25) for positioning the support members (11, 12, 13) with respect to the inner periphery guide section constituting members (15a, 15a) and the other one thereof is formed with support member positioning protrusions (26, 27, 12b) to be engaged with the support member positioning recesses (11b, 13b, 25).
According to the above embodiment, in the case where the support member, the escape passage constituting member and the inner periphery guide section constituting member are manufactured independently from the body of the movable member and also independently from each other, the number of constitutional members or parts increases and, hence, the assembling working may be made difficult. According to the present invention, however, since the support member and the escape passage constituting member are positioned with reference to the inner periphery guide section constituting member which is positioned to the body of the movable member, the working precision or performance of the support member, escape passage constituting member and inner periphery guide section constituting member can be improved. As a result, even in the case where the support member, the escape passage constituting member and the inner periphery guide section constituting member are manufactured independently from the body of the movable member and also independently from each other, these circulation passage constituting members never make worse the motion of the rolling members. Moreover, since the support member and the escape passage constituting member are positioned and assembled with the inner periphery guide section constituting member being one reference member, the support member, the escape passage constituting member and the inner periphery guide section constituting member can be easily assembled with high reproductivity.
Furthermore, in a further preferred embodiment of the present invention, a pair of side lids (5, 5) constituting outer periphery guide sections of the direction changing passages are mounted to both longitudinal end portions of the movable member body (4), both the end portions of the support member (11, 13) are inserted into the side lids (5, 5), and either one of the inner periphery guide section constituting members (15a, 15a) and the support members (11, 13) is formed with a positioning recess (11b, 13b) for positioning the support members with respect to the inner periphery guide section constituting members (15a, 15a) and the other one thereof is formed with support member positioning protrusions (26, 27) to be engaged with the support member positioning recesses (11b, 13b).
According to this invention, since both the end portions of the support members are inserted into the paired side lids mounted to the body of the movable member, the support member can be firmly fixed thereto. Moreover, in the case where both the end portion of the support member are fitted into the side lids, when it is required to carry out the assembling working, it is necessary that the support member is once inserted into one of the side lids, the rolling members are fitted and, then, the other side lid is inserted into the other end portion of the support member. In the process that the other side lid is inserted, there is a fear that the support member falls down and, hence, the side lids may not be precisely fitted to the support member. According to this invention, however, the support member can be positioned by the inner periphery guide section and the side lids, so that the support member is supported at two portions, and accordingly, the fear of falling-down of the support member in the assembling process will be reduced. Thus, the side lids can be simultaneously inserted into a plurality of support members, enabling the assembling process to be easy.
Furthermore, in a preferred embodiment of this invention, a number of rolling members (3, 3, - - - ) are held in series with predetermined distance by a rolling member support belt (10) having side edge portions (10d) projecting over both side end portions of the rolling members, and by assembling the support members (11, 12, 13) to the body (4) of the movable member, a guide section (43) for guiding the side edge portions (10d) of the rolling member support belt (10) is formed.
According to this invention, the rolling member support belt is held by the support member and the guide section formed by the body of the movable member, thus being prevented from coming off from the movable member. On the other hand, the rolling members can be held by the rolling member support belt, and accordingly, the rolling member support belt and the rolling members never come off from the movable member.
In a further preferred embodiment of the present invention, the track member is a track rail (1) and the movable member is a movable block (2) provided with a pair of sleeve portions disposed so as to oppose to both side surfaces of the track rail, the rolling member rolling portions are vertical two rows of rolling member rolling passages (1b, 1b) formed on each of lateral side surfaces of the track rail (1), totally, four rows thereof, the loaded rolling member rolling portions are vertical two rows of loaded rolling member rolling passages (4d, 4d) formed on each of inner side surfaces of the lateral sleeve portions (2b, 2b) of the movable block (2), totally, four rows thereof, the escape passage constituting passage includes vertical two rows thereof formed on each of the lateral sleeve portions (2b, 2b) of the movable block, totally, four rows thereof, the direction changing passages connect an upper loaded rolling member rolling passage and a lower rolling member escape passage (14, 14) and connect an lower loaded rolling member rolling passage and an upper rolling member escape passage so as to constitute grade separation structure, and the inner periphery guide section constituting member is composed of a pair of divided blocks (15a, 15b) divided in the longitudinal direction of the track rail (1).
According to this invention, the inner periphery guide sections to which the direction changing passages in grade separation can be easily manufactured.
In a still further preferred embodiment of this invention, either one of the paired divided blocks (15a, 15b) is formed with a positioning recess (28) for positioning the paired divided blocks and the other one thereof is formed with a divided block positioning protrusion (33) to be engaged with the divided block positioning recess (28).
According to this invention, even in the case of the divided inner periphery guide section, the inner periphery guide section can be assembled with high precision.
In a still further preferred embodiment of the present invention, the support members (11, 12, 13) include a first support member (11) disposed above the upper loaded rolling member rolling passage (4d), a second support member (12) disposed between the upper loaded rolling member rolling passage (4d) and the lower rolling member rolling passage (4d) and a third support member (13) disposed below the lower loaded rolling member rolling passage (4d).
According to this invention, the second support member is commonly utilized with the upper loaded rolling member rolling passage and the lower rolling member rolling passage, so that the number of the parts or members to be used can be reduced in comparison with the case where the second support members are disposed respectively to the upper loaded rolling member rolling passage and the lower rolling member rolling passage.
Still furthermore, the object of the present invention mentioned above can be also achieved by a motion guide device which comprises a track member (1) provided with rolling member rolling portions (1b, 1b) and a movable member (2) disposed to be movable along the track member (1) through a number of rolling members (3, 3, - - - ) and in which the movable member (2) is provided with loaded rolling member rolling portions (4d, 4d) corresponding to the rolling member rolling portions (1b, 1b) of the track member (1), rolling member escape passages disposed in parallel to the loaded rolling member rolling portions (4d, 4d) with a predetermined distance and a pair of direction changing passages connecting the loaded rolling member rolling portions (4d, 4d) and the rolling member escape passages to thereby circulate the rolling members,
wherein support members (11, 12, 13) extending along both side edges of the loaded rolling member rolling portions (4d, 4d) and a pair of inner periphery guide section constituting members (15a, 15b) constituting the inner peripheral portions of the direction changing passages are formed to be independent from a body (4) of the movable member and also independent from each other and are assembled to the body (4) of the movable member, and the rolling member escape passages are constituted by through holes perforated to the body (4) of the movable member.
According to this invention, since the support members and the inner periphery guide section constituting members are formed independently from the body of the movable member and from each other, these members can be manufactured by preliminarily calculating respective shrinkage cavities of the support members and the inner periphery guide section constituting members. As a result, the long and thin support members can be prevented from being flexed and the inner periphery guide section constituting members can be also prevented from being opened.